Du bon usage de la science : de l’optique moralisée à l’optique de la morale

ln Littérature et anthropologie, Louis Van Delft makes a distinction between « moralized anatomy » (which implies an ediffing reading of a dissected body) and « moral anatomy » (in which the moral analysis follows the model of dissection). The history of the literary uses of optics in seventeenth-century France requires a similar qualification : moralized optics, moral optics. When he sets out to « moralize the whole optic », Father Marin Mersenne tries first to give a spiritual foundation for the study of this science, by pointing out that it can offer an allegory of the Mysteries of faith, to those who can use it in the appropriate way, and hence provide a whole store of figures to the masters of sacred eloquence. Like Pascal, the French moralists of the scond half of the seventeenth century (and beyond, someone like Chamfort) exploit terms and categories deriving from optics (and more particularly perspective), in order to build a model for moral analysis : what is at stake is to formulate the principles underlying the way behaviours and merits can be measured - « in the realm of truth and morality » -, according to the model that governs the configuring and perception of the visual space - « in painting ». Somewhere along the evolution that leads from the moralized optics as it was theorized by Mersenne to the optics of the moralists, an important epistemic shift can be perceived - summarized by a double process of secularization and literary appropriation